Sign front



F. SHIPMAN SIGN FRONT March 29, 1932.

Filed Oct. 9. 192a FIE E FIEJEl 31 15-4- FIE EL FlE 7 F1555- Patented Mar. 29, 1932 UNITED STATES IBEDEBIO 01 SAN FRANCISCO, CALIFORNIA SIGN IRON! Application filed October 9, 1928. Serial No. 311,271.

My invention relates to sign-fronts and is designed for use in connection with advertising signs of any character, outdoor or mdoor, artificially illuminated or illuminated by the use of daylight. A

In general it is the object of this invention to provide a sign or sign front consisting of a pair of super-imposed prismatlc optical media in combination with an indicia screen dis osed between said optical media.

other object of my invention is the provision of a sign-front having an indicia screen, the characters of which are animated.

More specifically an object of the invention is the provision of a sign-front consisting of a pair of super-imposed, prismatic optical media in combination with an indicia screen disposed between said optical media and provided'with means for moving said optical media relative to each other.

The invention possesses other ob ects, some of which with the foregoing will be set forth at length in the following description, where I shall outline in full thatforrn of the signfront of my invention, which 1 have selected for illustration in the drawings accompanying and forming part of the present specification. In said drawings I have shown one form of my invention, but it is to be understood that I do not limit myself to such form since the invention as set forth in the claims may be embodied in a plurality of forms.

Referring to the drawings:

Fi ure. 1 is a front elevation of a sign embodylng the objects of m invention and partially broken away to s ow its construction and operation;

Figure 2 is a horizontal section taken on the plane indicated by the line-2-2 of Fig. 1.

Figure 3 is a vertical section taken on the plane indicated by the line 3-3 of Fig. 1.

Figure 4 is a sectional view of the outer, prismatic optical media used in the modifications shown in Figs. 1, 2 and 3 and is taken on the plane indicated by the line 4-4 of Fig. 1.

Figure 5 is a-sectional view similar to that shown in Fig. 4, but taken on a plane indicated by the line 5-5 of Fig. 1.

Figure 6 is a diagrammatic representation of a letter I as it appears when subjected to the action of two superimposed, prismatic, optical media, the outer one of which is of the form as shown in Figs. 4 and 5.

Figure 7 is a diagrammatic representation of a letter I similar to that shown in Fig.

' 6 but with the outer prismatic, optical media .moved a distance equivalent to the radius of one of its spheroidal elements.

' The invention contemplates the use of a box or casing generally designated as 1 provided on one of its sides with a window 2. Movably disposed across the window 2 just within the casing is a prismatic, optical medium such asa prismatic glass plate 3, the lower edge of which is supported on rollers 4 mounted in the blocks 5. The blocks 5 may be secured to the floor of the casing in any suitable manner.

As best shown in'Figs. 2 and 3, the prismatic plate 3 is secured at its ends by any means such as channels 6, to a horizontally disposed yoke 7. The yoke 7 and plate 3 are made to reciprocate longitudinally by the action of a motor driven eccentric 8 secured.v to the yoke 7 by means of a link 9.

Vertically extending guide members 11, secured to the casing 1 by clips 12, maintain the prismatic plate 3 in its proper position against the window 2 and at the same time permit it to move longitudinally. However in order to allow for the unobstructed reciprocal movement of the yoke 7 the guide members 11 are notched as at 13 (shown in Fig. 3).

The inner exposed ends 17 of the guide members 11 are rabbetted inorder to accommodate a stationary 'inner prismatic glass plate 14. Disposed between the prismatic plates 3 and 14 and preferably secured to the prismatic plate 14 is a stenciled indicia screen 15. If desired this stencil may be painted. directly on the prismatic plate 14 but since it may be found advantageous to be able to change the stencil without necessarily changing the prismatic plate, this alternative'has its disadvantages.

Any available method of illuminating the sign front as above described, may be used, although in the embodiment shown in'the drawings I have shown the use of a reflector the I.

16 disposed at an angle of substantially 45 within the casing 1. As may readily be seen this causes light entering the'casing thru its open top to be reflected to and thru the stenciled indicia screen.

' The phrase prismatic optical media is here used to designate any translucent material having a regularly or irregularly distorted surface. By using various combina- 'tions of different prismatic glass plates in combination with a stenciled indicia screen innumerable effects may be produced particularly when a plurality of variously colored color screens are interposed between the signfront and its source of light. The inner prismatic plate if regularly distorted disperses and reflects the various colors used in a more or less regular, fashion. The second and outer prismatic plate subjects the light passing thru the inner plate and the indicia screen to a further dispersion which produces some very beautiful effects. One of the combinations produces a mother of pearl effect.

Due to the laws governing reflection and refraction it can readily be appreciated that relative motion between the two prismatic plates used will animate the various characters on the stenciled indicia screen.

When an outer prismatic plate such as shown in Figs. 4 thru 7 is made to move horizontally across the stenciled indicia screen the upright elements of the characters on the indicia screen appear to rotate. This action is illustrated in Figs. 6 and 7. The letter I in each of these fi res is seen in dotted lines thru the prismatic plate 3. In Fig. 6 the center line of one row of spheroidal distortions is in alinement with the center line of In this position the 1 appears to have the contour as shown by the shading on the spheroidal distortions. When the plate 3 has been moved a distance equal to the radius of one of the spheroidal distortions as shown in Fig. 7, the apparent outlines of the I are shown by the shading in that figure. In the first position the I appears to be defined by a plurality of convex lines while in the second position it is defined by a plurality of concave lines and in moving from one of these extreme positions to the other the I itself appears to rotate.

my hand.

FREDERIC SHIPMAN.

Although the outer prismatic plate has been shown and described as havin a horizontal linear motion it may readily given a circular motion by any well known mechanical expedient. It has been found that it is preferable to use the outer prismatic plate rather than the inner. However, motion of either or both plates will produce very satisfactory results.

I claim:

1. A sign front comprising a light difl'using plate, an indicia screen superimposed thereon, a third plate having distorting media disposed in front of the indicia screen, 

